# Phase Locking Value and filtering

**URL:** <https://mne.discourse.group/t/phase-locking-value-and-filtering/263>\
**Category:** Mailing List Archive (read-only)\
**Tags:** list-archive\
**Created:** [October 4, 2010, 2:13pm UTC](https://mne.discourse.group/t/phase-locking-value-and-filtering/263 "2010-10-04T14:13:20Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/mne/original/1X/85cc6bd2b69cb698a166dc6d880fb550510d0144.jpeg) [@system](https://mne.discourse.group/u/system)\
**Post date:** [October 4, 2010, 2:13pm UTC](https://mne.discourse.group/t/phase-locking-value-and-filtering/263/1 "2010-10-04T14:13:20Z")

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Hi Elisabeth,  
&nbsp;&nbsp;&nbsp;&nbsp;It does sound like the PLVs you are seeing around the cutoff frequency of the filter are dominated by filtering ripples. Are you filtering the data before epoching? Using a good FIR filter before epoching with cutoffs far away from your frequencies of interest would probably be the ideal thing to do. Since the frequency resolution of the wavelet transform becomes progressively poorer at higher frequencies, edge effects can bleed over a large range of frequencies around the cutoff.

Regards,  
Hari

Elisabeth Fonteneau \<Elisabeth.Fonteneau at [mrc-cbu.cam.ac.uk](http://mrc-cbu.cam.ac.uk)\> wrote:

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**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/mne/original/1X/85cc6bd2b69cb698a166dc6d880fb550510d0144.jpeg) [@system](https://mne.discourse.group/u/system)\
**Post date:** [October 4, 2010, 2:17pm UTC](https://mne.discourse.group/t/phase-locking-value-and-filtering/263/2 "2010-10-04T14:17:22Z")

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Hi Hari,  
I am filtering the data when I am epoching with the function mne\_epochs2mat  
As far as I understand your recommendation is to use a cut off at 150 low pass and to stop the analysis at 100 Hz for example?

Thanks a lot again for your time  
Elisabeth